Control apparatus, image capturing apparatus, lens apparatus, image capturing system, control method, and storage medium

ABSTRACT

A control apparatus includes a motion vector detector configured to detect a motion vector, a calculator configured to calculate angular velocity information of an object based on the motion vector and an angular velocity detected by an angular velocity detector, an acquirer configured to acquire a result of an image stabilizing control in capturing a still image based on the angular velocity information of the object, and a controller configured to control a display unit so as to display the still image and information of the result of the image stabilizing control superimposed on the still image.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an image capturing apparatus that canprovide a follow-shot assist.

Description of the Related Art

A follow shot is an imaging technique for expressing a speedily movingobject. This imaging technology attempts to make a moving object stillon a fluid background as a result of that a photographer pans a camerain association with the moving object.

The photographer needs to pan the camera in conformity with the movingobject in this imaging technique, and an excessive high or low panningvelocity causes a blurred image of the object because of a differencebetween the moving velocity of the object and the panning velocity. Thefollow-shot assist as one solution for this problem is proposed as atechnique to assist the photographer in follow-shot imaging. Thefollow-shot assist is a method for absorbing the difference between themoving velocity of the object and the panning velocity by moving a shiftlens for an image stabilization based on the panning velocity and amotion vector of the object detected based on the image.

Japanese Patent Laid-Open No. (“JP”) 2015-197562 discloses an imagecapturing apparatus configured to calculate a follow-shot correctionamount based on a motion vector amount of an object image and a panningvelocity, to move a shift lens with still image capturing, and therebyto capture a beautiful follow-shot image.

However, the image capturing apparatus disclosed in JP 2015-197562 doesnot consider the calculated follow-shot correction amount beyond amovable range of the shift lens for the image stabilization (or an imagestabilizing control lens). When the photographer cannot obtain beautifulfollow-shot imaging, the photographer needs to determine based on theimage whether he improperly panned the camera or the follow-shot assistmade an improper image stabilization because a camera misapprehended theobject etc. Moreover, the photographer needs trial and error inimproving his panning when the panning was improper.

JP 2006-317848 discloses a follow-shot method for detecting a differencebetween an object velocity and a camera panning velocity and forcorrecting a shift amount corresponding to the difference using theimage stabilizing function. JP 2015-161730 discloses a method forimproving a detection accuracy of an object moving velocity by changingan output timing of a vibration detector according to an exposure timeperiod and a frame rate, and by conforming a motion vector amount of anobject image to the output timing of the vibration detector.

However, the methods disclosed in JPs 2006-317848 and 2015-161730 can beexecuted in a lens integrated camera in which a motion vector detector,an image stabilizing controller, and a follow-shot assist controller areprovided in the same body, and cannot be executed in a lensinterchangeable camera system.

In general, a CPU that controls a camera body in the lensinterchangeable camera system always performs parallel processing for avariety of installed functions, and follow-shot assist processing maydelay depending on the priority of the parallel processing. In the datacommunication (lens communication) through mount terminals between thecamera body and the interchangeable lens, the follow-shot assistcommunication may delay since communications for a focus lens control, adiaphragm control, a state acquisition etc. may interrupt.

In other words, in the lens interchangeable camera system, the lenscommunication at a predicted timing may be unavailable due to theunavailable lens communication band and the CPU load concentration.

Use of the motion vector and lens angular velocity having differentdetecting timings would cause an erroneous calculation of the objectangular velocity, a performance deterioration, and a malfunction. Thephotographer may capture a still image at an arbitrary timing. Even whenthe lens communication for the follow-shot assist is not completed, itis necessary to keep a release responsiveness and to realize thefollow-shot assist for correcting a moving component of the object. Inorder to improve the follow-shot assist performance in the lensinterchangeable camera system, it is necessary to properly control thetimings for the motion vector and the lens angular velocity.

SUMMARY OF THE INVENTION

The present invention provides a control apparatus, an image capturingapparatus, a lens apparatus, a control method, and a storage medium,which can feed back a follow-shot assist result to a photographer when afollow-shot correction amount exceeds a movable range of an imagestabilizing control lens, or improve a follow-shot assist performance.

A control apparatus according to one aspect of the present inventionincludes a motion vector detector configured to detect a motion vector,a calculator configured to calculate angular velocity information of anobject based on the motion vector and an angular velocity detected by anangular velocity detector, an acquirer configured to acquire a result ofan image stabilizing control in capturing a still image based on theangular velocity information of the object, and a controller configuredto control a display unit so as to display the still image andinformation of the result of the image stabilizing control superimposedon the still image.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a camera system according to eachembodiment.

FIG. 2 is a flowchart of an image-capturing synchronizing communicationprocess by a camera body according to each embodiment.

FIG. 3 is a flowchart of an exposure setting process by the camera bodyaccording to each embodiment.

FIG. 4 is a flowchart of still image capturing by the camera bodyaccording to each embodiment.

FIG. 5 is a flowchart of a reception process in a synchronizing signalcommunication by an interchangeable lens according to each embodiment.

FIG. 6 is a flowchart of a reception process in a setting communicationof a lens angular velocity detecting period by the interchangeable lensaccording to each embodiment.

FIG. 7 is a flowchart of a reception process in an object angularvelocity communication by the interchangeable lens according to eachembodiment.

FIG. 8 is a flowchart of a reception process in a still image capturingstart timing communication by the interchangeable lens according to afirst embodiment.

FIG. 9 is a flowchart of a reception process in a follow-shot assistresult communication by the interchangeable lens according to eachembodiment.

FIG. 10 is a timing chart of a follow-shot assist process by a camerasystem according to each embodiment.

FIG. 11 illustrates illustrative captured images displayed on the camerabody according to each embodiment.

FIG. 12 is a flowchart of a reception process in a still image capturingstart timing communication by the interchangeable lens according to asecond embodiment.

FIG. 13 is a flowchart of an exposure setting process by the camera bodyaccording to each embodiment.

FIG. 14 is a flowchart of an exposure process by the camera bodyaccording to each embodiment.

FIG. 15 is a flowchart of a reception process in a setting communicationof a lens angular velocity detecting period by the interchangeable lensaccording to each embodiment.

FIG. 16 is a flowchart of a reception process in an object angularvelocity communication by the interchangeable lens according to eachembodiment.

FIG. 17 is a flowchart of a reception process in an exposure starttiming communication by the interchangeable lens according to eachembodiment.

FIGS. 18A, 18B and 18C are timing charts of a follow-shot assist processby a camera system according to a third embodiment.

FIG. 19 is an explanatory view of a method for calculating a driveamount of an image stabilizing controller according to the thirdembodiment.

FIG. 20 is a timing chart of a follow-shot assist process by a camerasystem according to a fourth embodiment.

FIG. 21 is an explanatory view of a calculation method of a drive amountof an image stabilizing controller according to the fourth embodiment.

DESCRIPTION OF THE EMBODIMENTS

Referring now to the accompanying drawings, a detailed description willbe given of embodiments of the present invention.

First Embodiment

Referring now to FIG. 1, a description will be given of a camera systemaccording to a first embodiment of the present invention. FIG. 1 is ablock diagram of a camera system 10 (image capturing apparatus or imagecapturing system). In this embodiment, the camera system 10 includes acamera body 100 (image capturing apparatus or image capturing apparatusbody) and an interchangeable lens 200 (lens apparatus) attached to anddetached from the camera body 100. This embodiment is not limited tothis example, and is applicable to an image capturing apparatus in whichthe image capturing apparatus body is integrated with the lensapparatus.

As illustrated in FIG. 1, the interchangeable lens 200 is detachablyattached to the camera body 100 of this embodiment via a lens mount unit12. The interchangeable lens 200 attachable to the camera body 100includes an image capturing optical system that includes a focus lens201, a zoom control unit 202, a diaphragm (aperture stop) 203, and animage stabilizing control lens 204. FIG. 1 illustrates one lens thatrepresents each of the focus lens 201, the zoom control unit 202 (zoomlens), and the image stabilizing control lens 204, but each lens mayinclude a lens unit that includes a plurality of lenses. A light fluxformed via the image capturing optical system is introduced to an imagesensor 102 and forms on an optical image on the image sensor 102.

A description will now be given of a configuration of the camera body100. A shutter 101 controls an exposure amount to an image sensor 102.The image sensor 102 includes a CCD sensor or a CMOS sensor, andconverts the optical image of an object into an analogue image signal.In other words, the image sensor 102 photoelectrically converts theoptical image formed by the image capturing optical system, and outputsan image signal. The image sensor 102 may include a plurality of pixelsused for a focus detection (focus detecting pixels). An A/D converter103 converts the analogue image signal output from the image sensor 102into a digital image signal, and outputs the digital signal to an imageprocessor 140 and a memory controller 105. The optical image of theobject can be observed by an optical viewfinder 114 through mirrors 112and 113, while the mirror 112 moves down. A timing generator 104supplies a clock signal and a synchronizing signal to the image sensor102, the A/D converter 103, the image processor 140, the memorycontroller 105, and a system processor 130.

The image processor 140 performs a predetermined pixel interpolationprocess and a color conversion process for the digital image signal fromthe A/D converter 103 and data from the memory controller 105 andgenerates image data. The image processor 140 performs a predeterminedcalculation process with the digital image signal. The image processor140 determines an object position, and follows the object based on acolor and a shape of the object. The image processor 140 includes amotion vector detector 141. The motion vector detector 141 detects amotion vector (motion vector amount) based on the object position over aplurality of frames of the followed object. The object position includesan upper left coordinate, a height, and a width of the object. Thecalculated result of the image processor 140 is output to the systemcontroller 130 via the memory controller 105.

The memory controller 105 controls the A/D converter 103, the timinggenerator 104, the image processor 140, the memory 107, a recorder 108,and an image display unit 106. The output data from the A/D converter103 is written in the memory 107 and the recorder 108 via the imageprocessor 140 and the memory controller 150. The memory 107 and therecorder 108 stores captured still and motion images. The memory 107includes a nonvolatile memory, and is used for a working area of thesystem controller 130. The recorder 108 is used for an image recordingarea that includes a non-volatile memory attached to the inside oroutside of the camera body 100.

The image display unit 106 (display unit) includes an LCD, and displaysan image output from the A/D converter 103 or the image recorded in therecorder 108. The image display unit 106 can display an image capturingcondition, such as a shutter speed, a follow-shot assist result, and anobject position, by superimposing them on the image. As described above,the system controller 130 (controller) makes a control so as to make theimage display unit 106 display a still image on which information on animage stabilizing control result is superimposed. A shutter controller110 controls the shutter 101 in association with a mirror controller 111based on the control signal from the system controller 130. The mirrorcontroller 111 controls the mirror 112 based on a control signal fromthe system controller 130.

The system controller 130 controls the entire camera system 10 thatincludes the camera body 100 based on input signals from a shutterswitch 115 (SW1), a shutter switch 116 (SW2), a camera operation unit117, and a memory controller 105. In other words, the system controller130 controls the image sensor 102, the memory controller 105, theshutter controller 110, the mirror controller 111, the interchangeablelens 200 via an I/F 120 etc., in accordance with each of the above inputsignals.

The shutter switch 115 (SW1) instructs operation starts for an AFprocess, an AE process, an AWB process, etc. to the system controller130. The shutter switch 116 (SW2) instructs an exposure start to thesystem controller 130. The system controller 130 that has received theexposure start instruction controls the interchangeable lens 200 via themirror controller 111, the shutter controller 110, the memory controller105, and the I/F 120, and starts an exposure of the image sensor 102.The system controller 130 ends the exposure after a time period for theshutter speed passes. The system controller 130 converts a still imageexposed by the image sensor 102 into digital data via the A/D converter103, and saves it in the memory controller 105. In this case, the memorycontroller 105 saves the image capturing condition and the follow-shotassist result. Thereafter, the system controller 130 stores the stillimage stored in the memory controller 105, as JPEG and RAW data. Theimage capturing condition and the follow-shot assist result are embeddedin the still image data as EXIF information.

A camera operation unit 117 includes a variety of buttons, a touchpanel, a power on/off button, etc., and outputs a command accepted bythe operation by the photographer to the system controller 130. Inaccordance with the operation of the photographer via the cameraoperation unit 117, the system controller 130 selects each operationmode, such as an AF mode, and AE mode, and a follow-shot assist mode, asone of the variety of functions in the camera body 100. A camera powercontroller 118 controls an external battery and an internal battery ofthe camera body 100. Where the battery is detached or remaining batteryamount runs short, the camera power controller 118 emergently turns offa control over the camera body 100. In this case, the system controller130 shuts down the power supplied to the interchangeable lens 200.

An AF controller 131 is provided in the system controller 130, andcontrols the AF process in the camera body 100. In the AF process, theAF controller 131 calculates a drive amount of the focus lens 201 basedon the lens information, such as a focus position and a focal length,obtained from the interchangeable lens 200 via the I/F 120 and the AFevaluation value in accordance with the AF mode. The drive amount of thefocus lens 201 is input into the interchangeable lens 200 via the lenscommunication controller 133 in the system controller 130 and the I/F120. For example, in the phase difference AF mode, the AF controller 131calculates the drive amount of the focus lens 201 based on a phasedifference AF evaluation value etc. obtained by introducing the opticalimage of the object into the mirror 112, an unillustrated focusdetecting sub mirror, and an unillustrated focus state determining unit.In a contrast AF mode, the AF controller 131 calculates the drive amountof the focus lens 201 based on a contrast AF evaluation value calculatedin the image processor 140. In an image-plane phase difference AF mode,the AF controller 131 calculates the drive amount of the focus lens 201based on an image-plane phase difference AF evaluation value output frompixels (used for the focus detection) on the image sensor 102. The AFcontroller 131 switches a position of the AF frame used to calculate theevaluation value in accordance with an AF evaluation mode such as asingle point AF mode, a multi-point AF mode, and a face detection AFmode.

An AE controller 132 is provided in the system controller 130, andcontrols the AE process in the camera body 100. In the AE process, theAE controller 132 calculates an AE control amount (such as a diaphragmcontrol amount, a shutter control amount, and an exposure sensitivity)based on lens information, such as an open F-number and a focal length,obtained from the interchangeable lens 200 via the I/F 120, and an AEevaluation value in accordance with the AE mode. The diaphragm controlamount is input into the interchangeable lens 200 via the lenscommunication controller 133 and the I/F 120. The shutter control amountis input into the shutter controller 110. The exposure sensitivity isinput into the image sensor 102. For example, in a viewfinder imagingmode, the AE controller 132 calculates the AE control amount based onthe AE evaluation value obtained by introducing the optical image of theobject into the mirrors 112 and 113 and an unillustrated brightnessdetermining unit. In the live-view imaging mode, the AE controller 132calculates the AE control amount based on the AE evaluation valuecalculated in the image processor 140. The AE controller 132 selects anAE frame position and a weighting value used to calculate the evaluationvalue in accordance with a photometry mode, such as an evaluationphotometry mode, an average photometry mode, and a face detectionphotometry mode.

An follow-shot assist controller 134 is provided in the systemcontroller 130, and controls the follow-shot assist process in thecamera body 100. The follow-shot assist function is available where thelive-view imaging mode is set and the attached interchangeable lens 200is compatible with the follow-shot assist. The follow-shot assistfunction is unavailable, the follow-shot assist controller 134 controlsa flow amount in an image in accordance with the follow-shot assistmode. More specifically, the follow-shot assist controller 134 notifiesthe AE controller 132 of a shutter control amount such that a blur anglein exposure can be an arbitrary amount and controls the flow amount inthe image, based on the angular velocity information etc. obtained fromthe angular velocity detector 208 in the interchangeable lens 200.

On the other hand, when the follow-shot assist function is available,the follow-shot assist controller 134 instructs the availability of thefollow-shot assist process to the interchangeable lens 200 via the I/F120 in accordance with the follow-shot assist mode. The follow-shotassist controller 134 calculates angular velocity information of theobject, such as an object angular velocity and an object angularacceleration, based on the lens information, such as the lens angularvelocity information and the focal length, obtained from theinterchangeable lens 200 via the I/F 120, the motion vector amount inputfrom the image processor 140, etc. Thus, the follow-shot assistcontroller 134 serves as a calculator configured to calculate (obtain)the angular velocity information of the object based on the motionvector and the angular velocity detected by the angular velocitydetector 208.

The follow-shot assist controller 134 calculates a set value of a lensangular velocity detecting period based on the frame rate, the shutterspeed, etc. such that the lens angular velocity detecting periodcoincides with the motion vector detection period. The set value of thelens angular velocity detecting period is input into the interchangeablelens 200 via the lens communication controller 133 and the I/F 120. Theset value of the lens angular velocity detecting period contains angularvelocity ID information. The angular velocity ID information is added sothat the follow-shot assist controller 134 can identify which period thelens angular velocity received from the interchangeable lens 200 belongsto. The lens angular velocity information also contains the angularvelocity ID information, and the angular velocity ID information and thelens angular velocity information are tagged with each other and sent tothe camera body 100.

A lens communication controller 133 is provided in the system controller130, and controls a communication process between the camera body 100and the interchangeable lens 200. When the lens communication controller133 detects the attachment of the interchangeable lens 200 via the I/F200, the lens communication controller 133 starts the communicationbetween the camera body 100 and the interchangeable lens 200 so as toreceive necessary lens information and to send necessary camerainformation and a necessary driving command. For example, assume thatthe live-view imaging mode is set and the attached interchangeable lens200 is compatible with the follow-shot assist. Then, when animage-capturing synchronizing signal is input from the timing generator104, the lens communication controller 133 executes a synchronizingsignal communication for notifying a communication start delay time fromwhen the image-capturing synchronizing signal is input to when thecommunication starts. When the exposure by the shutter switch 116 (SE2)ends, the lens communication controller 133 receives follow-shot assistresult information from the interchangeable lens 200. When theimage-capturing synchronizing signal is input from the timing generator104 in the live-view imaging mode, the lens communication controller 133receives various lens information simultaneously, such as a focus lensposition, a focus lens state, a diaphragm state, and a focal length.

The I/F 120 is an interface for the communication between the camerabody 100 and the interchangeable lens 200. The I/F 120 sends andreceives the lens information, the control command, etc. through acommunication with an electric signal via the connector 20 between thesystem controller 130 in the camera body 100 and the lens controller210.

Next follows a description of the configuration of the interchangeablelens 200. The focus lens 201 moves in a direction along an optical axisOA (optical axis direction) and adjusts a focus (focus state) in theimage capturing optical system. The focus controller 205 is controlledby the lens controller 210, and drives the focus lens 201. The focuscontroller 205 outputs focus information, such as a position of thefocus lens 201, to the lens controller 210.

The zoom control unit 202 moves in the optical axis direction andchanges a focal length of the image capturing optical system. The zoomcontroller 206 is controlled by the lens controller 210, and drives azoom control unit 202. The zoom controller 206 outputs zoom information,such as a focal length, to the lens controller 210. The diaphragm 203has a variable aperture diameter (F-number) and changes a light quantityaccording to the aperture diameter. The diaphragm controller 207 iscontrolled by the lens controller 210, and drives the diaphragm 203. Thediaphragm controller 207 outputs the diaphragm information, such as anF-number, to the lens controller 210.

An image stabilizing control lens 204 moves in a direction orthogonal tothe optical axis OA (optical axis orthogonal direction), and reduces animage blur caused by a camera vibration or a manual blur. The imagestabilizing controller 209 is controlled by the lens controller 210, anddrives the image stabilizing control lens 204. The image stabilizingcontroller 209 outputs image stabilizing information, such as an imagestabilizable range, to the lens controller 210.

The angular velocity detector 208 detects an angular velocity of theinterchangeable lens 200 (in the Yaw direction and in the Pitchdirection), and outputs the detected result to the lens controller 210.The angular velocity detector 208 is controlled by the lens controller210. The angular velocity detector can be provided into the camera body100.

A lens operation unit 211 includes a focus ring, a zoom ring, an AF/MFswitch, an IS (image stabilization) on/off switch, etc., and outputs acommand accepted by the operation of the photographer to the lenscontroller 210. The system controller 130 switches the operation modefor each type of function mounted on the interchangeable lens 200 inaccordance with the operation of the photographer on the lens operationunit 211. A memory 212 includes a nonvolatile memory.

The controller 210 controls the focus controller 205, the zoomcontroller 206, the diaphragm controller 207, the image stabilizingcontroller 209, the angular velocity detector 208, etc. in accordancewith the input signal from the lens operation unit 211 or the I/F 220.Thereby, the lens controller 210 controls the entire interchangeablelens 200. The lens controller 210 sends information input from eachcontroller and each detector to the camera body 100 via the I/F 220, inresponse to a lens information acquiring command received via the I/F220.

The I/F 220 is an interface for a communication between the camera body100 and the interchangeable lens 200. The I/F 220 sends and receives thelens information, the control command, etc. through a communication withan electric signal via the connector 20 between the system controller130 in the camera body 100 and the lens controller 210. As describedlater, the I/F 220 sends an image stabilizing control result(follow-shot assist result) after a still image is captured, to thecamera body 100.

Referring now to FIG. 2, a description will be given of theimage-capturing synchronizing communication process in the camera body100 according to this embodiment. FIG. 2 is a flowchart of theimage-capturing synchronizing communication process in the camera body100 in the live-view imaging mode where the attached interchangeablelens 200 is compatible with the follow-shot assist. The image-capturingsynchronizing communication process starts with the live-view imagingmode so that the lens controller 210 can communicate with the camerabody 130 at a timing of the image-capturing synchronizing signal.

Initially, in the step S201, the system controller 130 determineswhether the live-view imaging mod is continuing. Where the live-viewimaging is continuing, the flow moves to the step S202. Where thelive-view imaging is not continuing, the image-capturing synchronizingcommunication process of this flow ends.

In the step S202, the system controller 130 determines whether theimage-capturing synchronizing signal has been input. Where theimage-capturing synchronizing signal is input, the flow moves to thestep S203. Where the image-capturing synchronizing signal is not input,the flow returns to the step S201. In the step S203, the systemcontroller 130 stores the input time of the image-capturingsynchronizing signal as image-capturing synchronizing signal time in theunillustrated internal memory in the system controller 130 or the memory107. Next, in the step S204, the system controller 130 determineswhether there is an unprocessed lens communication. When there is anunprocessed lens communication, the flow moves to the step S205. Whenthere is no unprocessed lens communication, the flow moves to the stepS206. In the step S205, the system controller 130 completes theunprocessed lens communication and the flow moves to the step S206.

In the step S206, the system controller 130 determines whether thesynchronizing signal communication is to be executed. Where theinterchangeable lens 200 is compatible with the follow-shot assist andthe follow-shot assist mode is valid, the system controller 130determines that the synchronizing signal communication is to be executedand the flow moves to the step S207. Where the system controller 130determines that the synchronizing signal communication is not to beexecuted, the flow moves to the step S201.

In the step S207, the system controller 130 measures the time elapsedfrom the image-capturing synchronizing signal time, and stores the timeelapsed as the delay time (synchronizing signal communication delaytime) in the internal memory or the memory 107. Next, in the step S208,the system controller 130 communicates the synchronizing signal to theinterchangeable lens 200 via the I/F 120. The transmission data in thesynchronizing signal communication contains a synchronizing signal delaytime. Next, in the step S209, the system controller 130 communicates aset value communication of the lens annular velocity detecting period tothe interchangeable lens 200 via the I/F 120, and returns to the stepS201. As transmission data in the set value communication of the lensangular velocity detecting period, the system controller 130 sends theset value of the lens angular velocity detecting period input from thefollow-shot assist controller 134.

Due to the above process, the camera body 100 can notify theinterchangeable lens 200 of the image-capturing synchronizing signal,and sets the lens angular velocity detecting period.

Referring now to FIG. 3, a description will be given of an exposuresetting process in the camera body 100. FIG. 3 is a flowchart of anoperation of the exposure setting process in the camera body 100 in thelive-view imaging mode where the attached interchangeable lens 200 iscompatible with the follow-shot assist. The exposure setting process isexecuted for each frame in the live-view imaging mode for an exposurecontrol over the next frame.

Initially, in the step S301, the system controller 130 determineswhether the live-view imaging is continuing. Where the live-view imagingis continuing, the flow moves to the step S302. Where the live-viewimaging is not continuing, the exposure setting process of this flowends.

In the step S302, the system controller 130 determines whether it is theexposure setting timing of the image sensor 102 for the next frame.Where it is the exposure setting timing, the flow moves to the stepS303. Where it is not the exposure setting timing, the flow moves to thestep S301.

In the step S303, the system controller 130 calculates an exposure setvalue based on the AE control amount, the camera mode, etc. The systemcontroller 130 controls the exposure for the next frame by outputtingthe exposure set value to the memory controller 105. Next, in the stepS304, the follow-shot assist controller 134 determines whether thefollow-shot assist process is to be executed. Where the interchangeablelens 200 is compatible with the follow-shot assist and the follow-shotassist mode is valid, the follow-shot assist controller 134 determinesthat the follow-shot assist process is to be executed and the flow movesto the step S305. Where the follow-shot assist controller 134 determinesthat the follow-shot assist process is not to be executed, the flowreturns to the step S301.

In the step S305, the follow-shot assist controller 134 calculates theset value of the lens angular velocity detecting period as a relativetime period from the image-capturing synchronizing signal based on theexposure setting for the next frame, etc. such that the motion vectordetecting period coincides with the lens angular velocity detectingperiod. The calculated set value of the lens angular velocity detectingperiod is sent to the interchangeable lens 200 in the step S209. The setvalue of the lens angular velocity detecting period contains angularvelocity ID information. The angular ID information is added so that thefollow-shot assist controller 134 can identify which period the lensangular velocity received from the interchangeable lens 200 belongs to.The lens angular velocity information also contains the angular velocityID information, and the angular velocity ID information and the lensangular velocity information are tagged with each other and sent to thecamera body 100.

Next, in the step S306, the follow-shot controller 134 calculates theangular velocity information of the object based on the lensinformation, such as the lens angular velocity information and the focallength received form the interchangeable lens 200, and the motion vectoramount input from the image processor 140. The angular velocityinformation of the object contains the object angular velocity and theobject angular acceleration. The follow-shot assist controller 134inputs the calculated angular velocity information of the object intothe lens communication controller 133. The angular velocity informationof the object contains the lens angular velocity information acquiringtime period corresponding to the lens angular velocity information usedfor the calculation. The follow-shot assist controller 134 stores theobject position detected by the image processor 140 in the memory 107via the memory controller 105. One or more object positions containingthe latest value are stored in the memories 107. When these processesend, the system controller 130 moves to the step S307. In the step S307,the lens communication controller 133 communicates the object angularvelocity so as to send to the object angular velocity information to theinterchangeable lens 200, and moves to the step S301. In thisembodiment, the reception data in the object angular velocitycommunication contains the lens angular velocity information.

Due to the above processes, this embodiment can control the exposure forthe next frame and set the lens angular velocity detecting period to benotified to the interchangeable lens 200 with the next image-capturingsynchronizing signal. This embodiment can notify the interchangeablelens 200 of the object angular velocity and obtain the lens angularvelocity information from the interchangeable lens 200.

Referring now to FIG. 4, a description will be given of a live-viewstill image imaging process in the camera body 100. FIG. 4 is aflowchart of a still image imaging process (live-view still imageimaging process) in the camera body 100. FIG. 4 illustrates an operationof the live-view still image imaging process in the camera body 100 inthe live-view imaging mode where the attached interchangeable lens 200is compatible with the follow-shot assist. The live-view still imagecapturing process starts with a still image capturing start command viathe shutter switch 116 in the live-view imaging mode.

Initially, in the step S401, the system controller 130 notifies theinterchangeable lens 200 of the still image capturing start timing via acommunication with the lens communication controller 133. Next, in thestep S402, the system controller 130 controls the shutter controller 110and the image sensor 102, executes the still image exposure process, andobtains image data. The image data is stored in the memory 107 via theimage processor 140 and the memory controller 105. When the processends, the flow moves to the step S403. In the step S403, the systemcontroller 130 notifies the interchangeable lens 200 of a still imagecapturing end timing via a communication with the lens communicationcontroller 133.

Next, in the step S404, the lens communication controller 133 determineswhether the follow-shot assist process is to be executed. Where theinterchangeable lens 200 is compatible with the follow-shot assist andthe follow-shot assist mode is valid, the lens communication controller133 determines that the follow-shot assist process is to be executed,and moves to the step S405. Where the follow-shot assist process is notto be executed, the flow moves to the step S406.

In the step S405, the lens communication controller 133 executes acommunication for receiving follow-shot assist result information fromthe interchangeable lens 200. Herein, the lens communication controller133 (acquirer) acquires the image stabilizing control result(follow-shot assist result) in the still image capturing executed basedon the angular velocity information of the object. The lenscommunication controller 133 may obtain the image stabilizing controlresult from the interchangeable lens 200 by a communication with theinterchangeable lens 200 after the still image is captured.

Next, in the step S406, the system controller 130 prepares EXIFinformation to be added to the image file. The EXIF information isrecorded in the memory 107 via the memory controller 105. In thisembodiment, the EXIF information contains an image capturing condition,such as the lens information, the shutter speed, and the F-number, andfollow-shot assist result information received in the step S405. Thefollow-shot result information contains a success or failure of thefollow-shot assist, an object angular velocity V, which will bedescribed later, a follow-shot assist amount average value Ga, and apanning amount average value ga. The EXIF information contains thelatest object position stored in the memory 107 in the step S306.

Next, in the step S407, the system controller 130 controls the imageprocessor 140 and prepares an image file based on the image data and theEXIF information. The system controller 130 stores the image data in therecorder 108 after storing the image data in the memory 107 via thememory controller 105. Next, in the step S408, the system controller 130displays the image data stored in the memory 107 on the image displayunit 106. In this case, the system controller 130 displays andsuperimposes on the image (image data) the image capturing condition,the follow-shot assist result, and the object position contained in theEXIF information of the image data. Referring now to FIG. 11, adescription will be given of the display contents of the image displayunit 106 later.

Due to the above processes, the result of the follow-shot assistprovided to the exposure can be obtained from the interchangeable lens200, and the follow-shot assist result is recorded in the obtained imagedata and displayed on the image display unit 106.

Referring now to FIG. 5, a description will be given of a receptionprocess in the synchronizing signal communication by the interchangeablelens 200. FIG. 5 is a flowchart of the reception process in thesynchronizing signal communication by the interchangeable lens 200. FIG.5 illustrates a process that starts when the interchangeable lens 200compatible with the follow-shot assist receives the synchronizing signalcommunication from the camera body 100 in the live-view imaging mode.

Initially, in the step S501, the lens controller 210 stores acommunication time by storing a current time of a free-run timer usedfor time control in the interchangeable lens 200. This time is stored inthe unillustrated internal memory in the lens controller 210 or memory212.

Next, in the step S502, the lens controller 210 determines whether asynchronizing signal with a predetermined communication data length hasbeen communicated (whether all data are completely transmitted andreceived). Where all data has not yet been completely communicated(transmitted or received), the step S502 is repeated until all data iscompletely communicated. Where all data has been completelycommunicated, the flow moves to the step S503. In the step S503, thelens controller 210 subtracts the delay time contained in the receptiondata in the synchronizing signal communication (synchronizing signaldelay time period) from the time stored in the step S501 (time when thecommunication started). Thereby, the time of the image-capturingsynchronizing signal in the interchangeable lens 200 (inter-lensimage-capturing synchronizing signal) can be calculated (set) whichcoincides with the image-capturing synchronizing signal in timing in thecamera body 100.

Due to the above processes, the interchangeable lens 200 can recognizethe inter-lens image-capturing synchronizing signal time that coincideswith the image-capturing synchronizing signal timing in the camera body100.

Referring now to FIG. 6, a description will be given of a receptionprocess in the set value communication of the lens angular velocitydetecting period by the interchangeable lens 200. FIG. 6 is a flowchartof the reception process in the set value communication of the lensangular velocity detecting period by the interchangeable lens 200. FIG.6 illustrates a process that starts when the interchangeable lens 200compatible with the follow-shot assist receives the set valuecommunication of the lens angular velocity detecting period from thecamera body 100 in the live-view imaging mode.

Initially, in the step S601, the lens controller 210 determines whetherthe set value communication of predetermined lens angular velocitydetecting period has been communicated with a communication data length(whether all data has been completely transmitted and received). Whereall data has not yet been completely communicated (transmitted orreceived), the step S601 is repeated until all data is completelycommunicated. Where all data has been completely communicated, the flowmoves to the step S602.

In the step S602, the lens controller 210 calculates the lens angularvelocity detecting period based on the lens angular velocity detectingperiod contained in received data in the set value communication of thelens angular velocity detecting period and the time of the inter-lensimage-capturing synchronizing signal calculated in the step S503. Thelens controller 210 obtains the lens angular velocity in the lensangular velocity detecting period from the angular velocity detector208. The lens controller 210 adds the angular velocity ID informationcontained in the set value communication of the lens angular velocitydetecting period and the lens angular velocity information acquiringtime to the lens angular velocity information, and stores the result inthe internal memory or the memory 212. The lens controller 210 storesthat the follow-shot assist is valid in the memory 212.

Due to the above processes, the interchangeable lens 200 can set thelens angular velocity detecting period that coincides with the motionvector detecting period in the camera body 100.

Referring now to FIG. 7, a description will be given of a receptionprocess in an object angular velocity communication by theinterchangeable lens 200. FIG. 7 is a flowchart of the reception processin the object angular velocity communication by the interchangeable lens200. FIG. 7 illustrates a process that starts when the interchangeablelens 200 compatible with the follow-shot assist receives the objectangular velocity communication from the camera body 100 in the live-viewimaging mode.

Initially, in the step S701, the lens controller 210 prepares for orstores the lens angular velocity information in the transmission bufferso as to send the lens angular velocity information stored in the stepS602 to the camera body 100. Next, in the step S702, the lens controller210 determines whether the object angular velocity has been communicatedwith a predetermined communication data length (whether all data hasbeen completely transmitted and received). Where all data has not yetbeen completely communicated (transmitted or received), the step S702 isrepeated until all data is completely communicated. Where all data hasbeen completely communicated, the flow moves to the step S703. In thestep S703, the lens controller 210 stores the object angular velocityinformation in the internal memory or the memory 212 so as to preparefor the exposure start timing.

Due to the above processes, the interchangeable lens 200 can set thelens angular velocity detecting period that coincides with the motionvector detecting period of the camera body 100.

Referring now to FIG. 8, a description will be given of a receptionprocess in the still image capturing start timing communication by theinterchangeable lens 200. FIG. 8 is a flowchart of the reception processin the still image capturing start timing communication in theinterchangeable lens 200. FIG. 8 is a process that starts when theinterchangeable lens 200 compatible with the follow-shot assist receivesthe still image capturing start timing communication from the camerabody 100 in the live-view imaging mode in this embodiment.

Initially, in the step S801, the lens controller 210 determines whetherstill image capturing requires the follow-shot assist process. Morespecifically, the lens controller 210 makes the determination byreferring to the area in the memory 212 written in the step S602. Wherethe follow-shot assist process is to be executed, the flow moves to thestep S802. Where the follow-shot assist process is not to be executed,the flow moves to the step S808.

In the step S802, the lens controller 201 (predictor) predicts an objectangular velocity at the current time based on the object angularvelocity information stored in the step S703 and the current time(calculates the predicted angular velocity of the object before thestill image is captured). The lens controller 210 makes a predictivecalculation expressed by the following expression (1) where T is thecurrent time, V is the object angular velocity at the current time T, ν,a, and t are the object angular velocity, the object angularacceleration, and the lens angular velocity information acquiring timecontained in the object angular velocity information, although thepredictive calculation is not limited to the expression (1) and may useanother expression or method.

V=ν+a*(T−t)  (1)

Next, in the step S803, the lens controller 210 (image stabilizingcontroller) controls the image stabilizing controller 209 by using theangular velocity information of the object at the current time, andexecutes the follow-shot assist process. In other words, the lenscontroller 210 controls the image stabilization in capturing the stillimage by using the object angular velocity information calculated basedon the angular velocity detected by the angular velocity detector 208,the motion vector detected by the motion vector detector 141. Forexample, the lens controller 210 performs a calculation as expressed inthe following expression (2) where G is a follow-shot assist amount, andg is a panning amount detected by the angular velocity detector 208 incapturing the still image, although a calculation method of thefollow-shot assist amount G is not limited to this example. The movingobject can be maintained stationary by controlling the image stabilizingcontrol lens 204 by a follow-shot assist amount in capturing the stillimage.

G=V−g  (2)

In the step S803, the lens controller 210 determines whether or not thestill image capturing is continuing. More specifically, where the camerabody 100 has not yet received the still image capturing end timingcommunication in the step S403, the lens controller 210 determines thatthe still image capturing is continuing. Where the still image capturingis continuing, the flow moves to the step S804. Where the still image isnot captured, the flow moves to the step S807.

In the step S804, the lens controller 210 determines via the imagestabilizing controller 209 whether or not the assist amount is within amovable range of the image stabilizing control lens 204 (whether theimage stabilizing lens 204 exceeds the movable range or reaches an imagestabilizing control end in capturing the still image). Where the assistamount is within the movable range of the image stabilizing control lens204 (where the image stabilizing control lens 204 does not exceed themovable range), the flow moves to the step S805. When the imagestabilizing control lens 204 is located outside the movable range (wherethe image stabilizing control lens 204 exceeds the movable range), theflow moves to the step S806.

In the step S805, the lens controller 210 executes the follow-shotassist process. More specifically, the lens controller 210 obtains apanning amount g from the angular velocity detector 208 and calculatesthe follow-shot assist amount G by using the expression (2). The lenscontroller 210 controls the image stabilizing control lens 204 by thefollow-shot assist amount G via the image stabilizing controller 209.The lens controller 210 stores the follow-shot assist amount G and thepanning amount g in the memory 212. After the step S805 is executed, theflow returns to the step S803.

In the step S806, the lens controller 210 stores a failure as thefollow-shot assist result in the memory 212. The lens controller 210calculates a follow-shot assist amount average value Ga and a panningamount average value ga as average values based on the object angularvelocity V calculated in the step S802, the follow-shot assist amount Gand the panning amount g stored in the step S805. The lens controller210 stores the follow-shot assist amount average value Ga and thepanning amount average value ga with the follow-shot assist result inthe memory 212.

In the step S807, the lens controller 210 stores a success as thefollow-shot assist result in the memory 212. The lens controller 210calculates the follow-shot assist amount average value Ga and thepanning amount average value ga as the average values based on theobject angular velocity V calculated in the step S802 and thefollow-shot assist amount G and the panning amount g stored in the stepS805. The lens controller 210 stores the follow-shot assist amountaverage value Ga and the panning amount average value ga with thefollow-shot assist result in the memory 212.

In the step S808, the lens controller 210 executes a normal imagestabilization by the image stabilizing process only with the angularvelocity (manual vibration amount) detected by the angular velocitydetector 208.

Due to the above processes, the interchangeable lens 200 can send theresult of the follow-shot assist provided to the still image capturing(exposure) to the camera body 100, and the camera body 100 can recordthe follow-shot assist result in the acquired image data.

Referring now to FIG. 9, a description will now be given of a receptionprocess in the follow-shot assist result communication by theinterchangeable lens 200. FIG. 9 is a flowchart of the reception processin the follow-shot assist result communication by the interchangeablelens 200. FIG. 9 illustrates a process that starts when theinterchangeable lens 200 compatible with the follow-shot assist receivesthe follow-shot assist result communication from the camera body 100 inthe live-view imaging mode.

Initially, in the step S901, the lens controller 210 prepares for orstores the follow-shot assist result in the transmission buffer so as tosend the follow-shot assist result, such as the object angular velocitypredictively calculated in the step S802, to the camera body 100. Next,in the step S902, the lens controller 210 determines whether the objectangular velocity has been communicated with a predeterminedcommunication data length (whether all data has been completelytransmitted and received). When all data has not yet been completelycommunicated (transmitted or received), the step S902 is repeated untilall data is completely communicated. When all data has been completelycommunicated, the reception process of this flow ends.

Due to the above processes, the interchangeable lens 200 can send thefollow-shot assist result, the object angular velocity V, thefollow-shot assist amount average value Ga, and the panning amountaverage value ga to the camera body 100.

Referring now to FIG. 10, a description will be given of the follow-shotassist process by the camera system 10 (that includes the camera body100 and the interchangeable lens 200). FIG. 10 is a timing chart of thefollow-shot assist process by the camera system 10. FIG. 10 illustratesa process timing of the camera system 10 in the follow-shot assist modeand the live-view imaging mode, where the attached interchangeable lens200 is compatible with the follow-shot assist.

An image-capturing synchronizing signal 1001 is a synchronizing signaloutputs from the timing generator 104. An image-capturing accumulation1002 is an accumulation period in the image sensor 102, and the electriccharges are read in order from the top on the image in response to theimage-capturing synchronizing signal 1001. A synchronizing signalcommunication 1003 represents a timing of the synchronizing signalcommunication executed in the step S208 in FIG. 2. A set valuecommunication of the lens angular velocity detecting period 1004represents a timing of a set value communication of the lens angularvelocity detecting period executed in the step S209 in FIG. 2.

An object angular velocity communication 1005 represents a timing in theobject angular velocity communication executed in the step S307 in FIG.3. A still image capturing start timing communication 1006 represents atiming for the still image capturing start timing communication executedin the step S401 in FIG. 4. A follow-shot assist result communication1007 represents a timing for the follow-shot assist result communicationexecuted in the step S405 in FIG. 4. A release timing 1018 represents atiming when the photographer issues a release command via the shutterswitch 116.

A lens angular velocity detecting period 1008 represents a lens angularvelocity detecting period set in the step S602 in FIG. 6. When the lensangular velocity detecting period elapses, the lens controller 210calculates the lens angular velocity corresponding to the period, addsthe angular velocity ID information contained in the set valuecommunication of the lens angular velocity detecting period and the lensangular velocity information acquiring time to the lens angular velocityinformation, and stores the result. An angular velocity output 1009represents an output from the angular velocity detector 208. The lenscontroller 210 samples the angular velocity output 1009 in the lensangular velocity detecting period 1008.

In response to the image-capturing synchronizing signal 1010, thesynchronizing signal communication 1011 starts and the lens controller210 calculates the inter-lens image-capturing synchronizing signal timecorresponding to the image-capturing synchronizing signal 1010.Thereafter, the set value of the lens angular velocity detecting periodcalculated so that the motion vector detecting period 1013 coincideswith the lens angular velocity detecting period 1014 is sent to theinterchangeable lens 200 by the set value communication of the lensangular velocity detecting period 1012. An object angular velocitycommunication 1015 notifies the camera body 100 of the lens angularvelocity information obtained when the lens angular velocity detectingperiod 1014 ends. The follow-shot assist controller 134 calculates theobject angular velocity information based on the lens angular velocityinformation and the motion vector information obtained in the motionvector detecting period 1013.

In response to a release timing 1019, the system controller 130 finishesthe exposure associated with the synchronizing signal after the currentexposure ends. The system controller 130 executes the still imagecapturing start timing communication 1016 after the still imagecapturing is prepared for the shutter 101 and the image sensor 102. Atthe same time, the shutter 101 is driven so as to start capturing astill image. When a shutter speed time instructed by the photographerelapses, the system controller 130 stops exposure by driving shutter101. Thereafter, the system controller 130 executes the follow-shotassist result communication 1017.

Referring now to FIG. 11, a description will be given of a displaymethod of a captured image in the step S408 in the live-view imagingmode where the attached interchangeable lens 200 is compatible with thefollow-shot assist. FIG. 11 illustrates an illustrative captured image(still image) displayed on the image display unit 106 in the camera body100 as a result of that the photographer follow-shots an object 1101with the follow-shot assist.

The system controller 130 displays an object position frame 1102(information on the object position in the still image) based on theobject position stored in the EXIF information. The system controller130 displays a follow-shot result 1103 (information on the imagestabilizing control result) representing a success or failure of thefollow-shot assist based on a follow-shot assist result stored in theEXIF information. Herein, the follow-shot result 1103 illustrates afailure of the follow-shot assist (“x” mark). When the follow-shotresult 1103 illustrates a success of the follow-shot assist, a “∘” markis displayed representing the success. The follow-shot result 1103 isinformation, for example, representing whether the image stabilizingcontrol lens 204 exceeds the movable range in capturing a still image(whether the image stabilizing control lens 204 reaches the imagestabilizing control end).

The system controller 130 displays an object moving direction 1104(information on the predicted angular velocity of the object) based onthe object angular velocity V stored in the EXIF information. The systemcontroller 130 displays a panning direction 1105 (information on anangular velocity in capturing a still image) based on the panning amountaverage value ga stored in the EXIF information. At this time, theobject moving direction 1104 and the panning direction 1105 aredisplayed with arrow sizes proportional to the absolute value of theangular velocity. Since the object position is superimposed on thecaptured image and displayed, the photographer can confirm whether ornot the follow-shot assist is applied to the object as intended by thephotographer. Given a large shift between the object moving direction1104 and the panning direction 1105, the photographer can recognize thepanning direction and velocity to be corrected.

This embodiment displays the follow-assist result superimposed on thecaptured image on the image display unit 106 only for a predeterminedtime period after the image is captured. However, this embodiment is notlimited to this example, and is applicable to a case where a capturedimage is read from the recorder 108 just after the image is captured.

While this embodiment discusses the object moving direction 1104 and thephotographer panning direction 1105 superimposed on the captured image,the photographer may display a corrected direction of the panningdirection based on the follow-shot assist amount average value Ga. Thecorrected direction of the panning direction coincides with a directionwith the follow-shot assist amount G of 0.

Where the follow-shot capturing cannot provide a beautiful image, thisembodiment can determine whether the photographer improperly panned thecamera or the camera misapprehended the object. Where the photographerimproperly panned the camera, the way of improving the panning directioncan be fed back to the photographer.

Second Embodiment

Next follows a description of a second embodiment according to thepresent invention. The first embodiment suddenly stops the imagestabilizing control lens 204 that has moved beyond the image stabilizingmovable range in capturing a still image. On the other hand, thisembodiment recalculates and reduces a follow-shot amount where thefollow-shot assist amount G becomes large enough to exceed the imagestabilizing movable range. In this embodiment, the configuration of thecamera system, the control flow of the camera body 100, and part of thecontrol flow of the interchangeable lens 200 are the same as those inthe first embodiment. Thus, a description thereof will be omitted. Thisembodiment discusses a control flow of the still image capturing starttiming communication different from that of the first embodiment amongthe control flows in the interchangeable lens 200.

Referring now to FIG. 12, a description will be given of a receptionprocess in the still image capturing start timing communication by theinterchangeable lens 200. FIG. 12 is a flowchart of the receptionprocess in the still image capturing start timing communication by theinterchangeable lens 200. FIG. 12 illustrates a process that starts whenthe interchangeable lens 200 compatible with the follow-shot assistreceives the still image capturing start timing communication from thecamera body 100 in the live-view imaging mode. FIG. 12 is different fromFIG. 8 in having the steps S1203, S1204, and S1209. The steps S1201,S1202, S1205 to S1208, S1210, and S1211 in FIG. 12 are similar to thesteps S801 to S808 in FIG. 8, and a description thereof will be omitted.

In the step S1203, the lens controller 210 confirms (determines) whetheran inter-second follow-shot assist amount that is a value made bydividing an estimated follow-shot assist amount Gs by a shutter speed Tvis equal to or higher than a predetermined threshold. The estimatedfollow-shot assist amount Gs corresponds to the follow-shot assistamount G calculated with, for example, the expression (2). Where theinter-second follow-shot assist amount is equal to or higher than thepredetermined threshold, the flow moves to the step S1204. Where theinter-second follow-shot assist amount is smaller than the predeterminedthreshold, the flow moves to the step S1205.

In the step S1204, the lens controller 210 recalculates the objectangular velocity V using the following expression (3) so that theinter-second follow-shot assist amount becomes equal to or lower thanthe threshold Gb.

Gs/Tv=(g−V)/Tv<Gb  (3)

In the step S1207, the lens controller 210 obtains the panning amount gfrom the angular velocity detector 208, and calculates the follow-shotassist amount G by using the expression (2). At this time, where theflow goes through the step S1204 (where the object angular velocity V isrecalculated), the recalculated object angular velocity V is used.

In the step S1209, the lens controller 210 determines whether the flowhas gone through the step S1204 (whether the object angular velocity Vhas been recalculated). Where the flow has gone through the step S1204,the flow moves to the step S1208. Where the flow has not gone throughthe step S1204, the flow moves to the step S1210.

Where the follow-shot assist amount G is large enough to exceed theimage stabilizing movable range, this embodiment recalculates the objectangular velocity so as to reduce the follow-shot assist amount and tofeed back the follow-shot capturing result to the photographer. Wherethe follow-shot assist fails, the first embodiment suddenly stops thefollow-shot assist control whereas this embodiment applies a moderatefollow-shot assist control and restrains a still image from beingunnaturally captured.

Third Embodiment

A camera system according to a third embodiment of the present inventionis the same as that described in FIG. 1, and a description thereof willbe omitted.

The image-capturing synchronizing communication process in the camerabody 100 according this embodiment is the same as that illustrated inFIG. 2, and a description thereof will be omitted.

Referring now to FIG. 13, a description will be given of an exposuresetting process by the camera body 100. FIG. 13 is a flowchart of theexposure setting process by the camera body 100 in the live-view imagingmode, where the attached interchangeable lens 200 is compatible with thefollow-shot assist. The exposure setting process starts for each framein the live-view imaging mode and controls an exposure of the nextframe.

In the step S1301, the system controller 130 determines whether thelive-view imaging is continuing. Where the live-view imaging iscontinuing, the flow moves to the step S1302. Where the live-viewimaging is not continuing, the exposure setting process of this flowends.

In the step S1302, the system controller 130 determines whether it is anexposure setting timing of the image sensor 102 for the next frame.Where it is the exposure setting timing, the flow moves to the stepS1303. Where it is not the exposure setting timing, the flow returns tothe step S1301.

In the step S1303, the system controller 130 calculates an exposure setvalue based on an AE control amount, a camera mode, etc. The systemcontroller 130 controls the exposure for the next frame by outputtingthe exposure set value to the memory controller 105. Next, in the stepS1304, the follow-shot assist controller 134 determines whether thefollow-shot assist process is to be executed. Where the interchangeablelens 200 is compatible with the follow-shot assist and the follow-shotassist mode is valid, the follow-shot assist controller 134 determinesthat the follow-shot assist process is to be executed and moves to thestep S1305. Where the follow-shot assist controller 134 determines thatthe follow-shot assist process is not to be executed, the flow returnsto the step S1301.

In the step S1305, the follow-shot assist controller 134 calculates theset value of the lens angular velocity detecting period as the relativetime period from the image-capturing synchronizing signal so that themotion vector detecting period coincides with (corresponds to) theangular velocity detecting period based on the exposure setting for thenext frame, etc. The set value of the calculated angular velocitydetecting period is sent to the interchangeable lens 200 in the abovestep S209.

Next, in the step S1306, the follow-shot assist controller 134 obtainsthe angular velocity detected by the angular velocity detector 208 andthe angular velocity detecting time information from the interchangeablelens 200 based on the set value of the lens angular velocity detectingperiod sent from the camera body 100 to the interchangeable lens 200. Asdescribed in FIG. 19A, the angular velocity information obtained in thestep S1306 is the angular velocity information in the angular velocitydetecting period that coincides with (corresponds to) the motion vectordetecting period for the last frame. The follow-shot assist controller134 receives (obtains) from the interchangeable lens 200 the angularvelocity information (lens angular velocity) and the angular velocitydetecting time information (lens angular velocity detecting time)correlated with each other. For example, as in communication commandsillustrated in Table 1, the follow-shot assist controller 134, such asthe lens communication controller 133 and the I/F 120, receives(obtains) the lens angular velocity and the lens angular detecting timefrom the same communication packet. In other words, the lens controller210 (I/F 220) sends the lens angular velocity and the lens angularvelocity detecting time through the same communication packet.

TABLE 1 DCL 0xAA Don't care Don't care (lens angular velocitycommunication command) DLC Don't Care Lens Lens angular angular velocityvelocity detecting time

Next, in the step S1307, the follow-shot assist controller 134calculates the angular velocity information of the object (containingthe object angular velocity and the object angular acceleration). Theobject angular velocity information is calculated based on the angularvelocity information obtained from the interchangeable lens 200 in thestep S1306, the angular velocity detecting time information, the lensinformation, such as a focal length, the motion vector amount input fromthe image processor 140, etc. The follow-shot assist controller 134outputs the calculated object angular velocity information to the lenscontroller 133.

Next, in the step S1308, the lens communication controller 133 executesthe object angular velocity communication so as to send the objectangular velocity information to the interchangeable lens 200. In thisembodiment, the follow-shot assist controller 134 (lens communicationcontroller 133) sends the object angular velocity information correlatedwith the angular velocity information acquiring time obtained from theinterchangeable lens 200 in the step S1306, to the interchangeable lens200. The follow-shot assist controller 134 in this case sends the objectangular velocity information (object angular velocity) and the angularvelocity detecting time information (lens angular velocity detectingtime) correlated with each other, to the interchangeable lens 200. Forexample, as in communication commands illustrated in table 2, thefollow-shot assist controller 134 sends the object angular velocity andthe lens angular velocity detecting time period from the samecommunication packet. In other words, the lens controller 210 (I/F 220)receives (obtains) the object angular velocity and the lens angularvelocity detecting time through same communication packet.

TABLE 2 DCL 0xBB Object Lens angular (object angular velocity angularvelocity communication command) velocity detecting time DLC Don't careDon't care Don't care

When the object angular velocity communication in the step S1308 ends,the flow returns to the step S1301.

Due to the above processes, the exposure for the next frame can becontrolled, and the next image-capturing synchronizing signal can setthe lens angular velocity detecting period to be notified to theinterchangeable lens 200. This embodiment can notify the interchangeablelens 200 of the object angular velocity, and obtain the angular velocityinformation from the interchangeable lens 200.

Referring now to FIG. 14, a description will be given of an exposureprocess by the camera body 100. FIG. 14 is a flowchart of the exposureprocess by the camera body 100. FIG. 14 illustrates an operation of alive-view exposure process in the camera body 100 in the live-viewimaging mode, where the attached interchangeable lens 200 is compatiblewith the follow-shot assist. The live-view exposure process starts withthe exposure start command via the shutter switch 116 (SW2) in thelive-view imaging mode.

Initially, in the step S1401, the system controller 130 notifies theinterchangeable lens 200 of the exposure start timing (image-capturingstart timing) via a communication with the lens communication controller133. Next, in the step S1402, the system controller 130 controls theshutter controller 110 and the image sensor 102, executes the exposureprocess, and obtains image data. The image data is stored in the memory107 via the image processor 140 and the memory controller 105.

Next, in the step S1403, the lens communication controller 133determines whether the follow-shot assist process is to be executed.Where the interchangeable lens 200 is compatible with the follow-shotassist and the follow-shot assist mode is valid, the lens communicationcontroller 133 determines that the follow-shot assist mode is to beexecuted and moves to the step S1404. Where the follow-shot assistprocess is not to be executed, the flow moves to the step S1405.

In the step S1404, the lens communication controller 133 executes thecommunication so as to receive the follow-shot assist result informationfrom the interchangeable lens 200. In the step S1405, the systemcontroller 130 prepares EXIF information to be added to an image file.The EXIF information is recorded in the memory 107 via the memorycontroller 105. In this embodiment, the EXIF information contains animage capturing condition (camera mode), such as lens information, ashutter speed, and an F-number, and the follow-shot assist resultinformation received in the step S1404.

Next, in the step S1406, the system controller 130 controls the imageprocessor 140 and prepares the image file based on the image data andthe EXIF information. The system controller 130 stores the image data inthe memory 107 via the memory controller 105, and records the image datain the recorder 108.

Due to the above processes, the result of the follow-shot assistperformed in the exposure can be obtained from the interchangeable lens200, and the follow-shot assist result can be recorded in the obtainedimage data or displayed on the image display unit 106.

When the set value of the lens angular velocity detecting period is sentfrom the camera body 100 to the interchangeable lens 200, the motionvector detection period of the camera body 100 can coincide with theangular velocity detecting period of the interchangeable lens 200 intiming. The angular velocity information detected by the interchangeablelens 200 is tagged (or correlated) with the detecting time of theangular velocity information and sent to the camera body 100. Thedetecting time of the angular velocity information is tagged (orcorrelated) with the object angular velocity information calculatedbased on the angular velocity information and the motion vectordetecting information, and sent to the interchangeable lens 200.Thereby, in the live-view release exposure process, which will bedescribed later, the image stabilizing controller 209 can be controlledso as to correctly control a moving amount of the object in exposure. Inother words, the proper correction is available even though a live-viewrelease exposure process is requested while the transmission of theangular velocity information to the camera body 100 and the transmissionprocess of the angular velocity information of the object from thecamera body 100 have not yet been completed. The proper correction isavailable even though the live-view release exposure process isrequested while the follow-shot assist communication has not yet beencompleted at the conceived timing.

Since a reception process in the synchronizing signal communication bythe interchangeable lens 200 is the same as that described withreference to FIG. 5, a description thereof will be omitted.

Referring now to FIG. 15, a description will be given of a receptionprocess in the set value communication of the lens angular velocitydetecting period by the interchangeable lens 200. FIG. 15 is a flowchartof the reception process in the set value communication of the lensangular velocity detecting period by the interchangeable lens 200. FIG.15 is a process that starts when the interchangeable lens 200 compatiblewith the follow-shot assist receives the set value communication of thelens angular velocity detecting period from the camera body 100 in thelive-view imaging mode.

Initially, in the step S1501, the lens controller 210 determines whetherthe set value communication of the predetermined lens angular velocitydetecting period has been communicated with a communication data length(whether all data has been completely transmitted and received). Whenall data has been completely communicated (transmitted and received),the step S1501 is repeated until all data is completely communicated.When all data has been completely communicated, the flow moves to thestep S1502.

In the step S1502, the lens controller 210 sets the lens angularvelocity detecting period based on the lens angular velocity detectingperiod contained in the received data in the set value communication ofthe lens angular velocity detecting period and the time of theinter-lens image-capturing synchronizing signal calculated in the stepS503. In other words, the lens controller 210 obtains the angularvelocity in the lens angular velocity detecting period from the angularvelocity detector 208 when the lens angular velocity detecting period(the period which the angular velocity detector 208 detects the angularvelocity) ends.

Next, in the step S1503, the lens controller 210 stores time information(lens angular velocity detecting time) when the angular velocitydetector 208 detects the angular velocity. The lens angular velocitydetecting time is stored, for example, in the (unillustrated) internalmemory in the lens controller 210 or the memory 212. More specifically,the lens controller 210 stores the current time in the free-run timerused to control time in the interchangeable lens 200. The stored time(time information) may be the central time in the period designated bythe set value of the lens angular velocity detecting period sent fromthe camera body 100. However, this embodiment is not limited to thisexample, and may be the start time or end time in that period designatedby the set value of the lens angular velocity detecting period.

Due to the above processes, the interchangeable lens 200 can set thelens angular velocity detecting period that coincides with the motionvector detecting period in the camera body 100.

Referring now to FIG. 16, a description will be given of a receptionprocess in the object angular velocity communication by theinterchangeable lens 200. FIG. 16 is a flowchart of the receptionprocess of the object angular velocity communication by theinterchangeable lens 200. FIG. 16 is a process that starts when theinterchangeable lens 200 compatible with the follow-shot assist receivesthe object angular communication from the camera body 100 in thelive-view imaging mode.

Initially, in the step S1601, the lens controller 210 sends the angularinformation (lens angular velocity) stored in the step S1602 and theangular velocity detecting time information (lens angular velocitydetecting time) stored in the step S1603 to the camera body 100. Hence,the lens controller 210 stores the information (data) in thetransmission buffer.

Next, in the step S1602, the lens controller 210 determines whether theobject angular velocity communication has been communicated by apredetermined communication data length (whether all data has beencompletely transmitted and received). When all data has not yet beencompletely communicated (transmitted and received), the step S1602 isrepeated until all data is completely communicated. When all data hasbeen completely communicated, the flow moves to the step S1603.

Next, in the step S1603, the lens controller 210 sends the angularvelocity information prepared in the step S1601 and the angular velocitydetecting time information to the camera body 100. Next, in the stepS1604, the lens controller 201 stores the object angular velocityinformation and the angular velocity detecting time information in thefollow-shot assist controller 134 so as to prepare for a request for alive-view release exposure process from the camera body 100. Asdescribed later with reference to FIG. 19A, when the lens angularvelocity detecting time received from the camera body 100 in the stepS1603 is the angular velocity detecting time information sent to thecamera body 100 correlated with the angular velocity information storedin the step S1503 in the interchangeable lens 200.

The interchangeable lens 200 sends the detecting time of the angularvelocity information to the camera body 100 and the camera boy 100 againsends it to the interchangeable lens 200 because a series ofcommunication processes in which the interchangeable lens 200 sends theangular velocity information to the camera body 100 and the camera body100 send the object angular velocity information to the interchangeablelens 200 are not synchronized with the live-view release exposureprocess. Even when the series of communication processes have not yetbeen completed, it is necessary to implement the follow-shot assistoperation in the live-view release exposure process. The configurationof this embodiment can guarantee that the object angular velocityinformation used to calculate a drive amount by which the imagestabilizing controller 209 corrects the moving amount of the object inexposure is synchronized with the lens angular velocity detecting timeas the predicted reference time. An unusual case will be described laterwhere the object angular velocity information may not be synchronizedwith the lens angular velocity detecting time as the predicted referencetime will be described with reference to a timing chart.

This embodiment describes the lens angular velocity informationcommunication sent from the interchangeable lens 200 to the camera body100 and the object angular velocity information from the camera body 100to the interchangeable lens 200 as separate communication processes, butis not limited to this example. This embodiment may define a data formatas a full duplex communication and execute one communication process.

Due to the above processes, the interchangeable lens 200 can set thelens angular velocity detecting period that coincides with the motionvector detecting period of the camera body 100, and can obtain theobject angular velocity information from the camera body 100.

Referring now to FIG. 17, a description will be given of a receptionprocess in the exposure start timing communication by theinterchangeable lens 200. FIG. 17 is a flowchart of the receptionprocess in the exposure start timing communication by theinterchangeable lens 200. FIG. 17 illustrates a process that starts whenthe interchangeable lens 200 compatible with the follow-shot assistreceives the exposure start timing communication from the camera body100 in the live-view imaging mode.

Initially, in the step S1701, the lens controller 210 determines whetheror not the exposure requires the follow-shot assist process. Forexample, the lens controller 210 makes this determination by referringto the area in the memory 212 written in the step S1502. When thefollow-shot assist process is to be executed, the flow moves to the stepS1702. When the follow-shot assist is not to be executed, the flow movesto the step S1704.

In the step S1702, the lens controller 210 (calculator) predicts theobject angular velocity at current time based on the object angularvelocity information stored in the step S1603 and the angular velocitydetecting time information. In other words, the lens controller 210calculates a predicted angular velocity of the object. The lenscontroller 210 performs a predictive calculation as expressed by theexpression (1) where T is the current time and V is an object angularvelocity at the current time T.

In the expression (1), “ν” is an object angular velocity (object angularvelocity information) sent from the interchangeable lens 200 to thecamera 100 in the step S1603 and obtained by the camera body 100 in thestep S306, “a” is an object angular acceleration (object angularacceleration information) obtained by the camera body 100 in the stepS306, and “t” is an angular velocity information acquiring time (lensangular velocity information acquiring time) obtained by the camera body100 in the step S1306. However, the predictive calculation is notlimited to the expression (1), and may use another expression or anothermethod.

Next, in the step S1703, the lens controller 210 controls the imagestabilizing controller 209 by using the object angular velocity V at thecurrent time, and executes the follow-shot assist process. For example,the lens controller 210 obtains the image stabilizing amount (panningamount) g from the angular velocity detector 208 and calculates thefollow-shot assist image stabilizing amount G with the expression (2),although the calculation method of the follow-shot assist amount G isnot limited to this calculation. The moving object can be maintainedstationary by controlling the image stabilizing control lens 204 so asto cancel out the follow-shot assist image stabilizing amount inexposure.

In the step S1704, the lens controller 210 performs an image stabilizingprocess (image stabilizing control) only with an image stabilizingamount from the angular velocity detector 208, and thereby performs ausual image stabilizing correction.

Due to the above processes, the interchangeable lens 200 can send theresult of the follow-shot assist performed in exposure to the camerabody 100, and the camera body 100 can record the acquired image data inthe follow-shot assist result.

A reception process in the follow-shot assist result communication bythe interchangeable lens 200 is the same as that described in FIG. 9,and a description thereof will be omitted.

Due to the processes in FIG. 9, the interchangeable lens 200 can obtainthe object angular velocity that reflects the time elapsed from when thelens angular velocity detecting time is obtained to when the exposurestarts, and can perform an accurate follow-shot assist.

Referring now to FIG. 18A, a description will be given of the camerasystem 10 (that includes the camera body 100 and the interchangeablelens 200). FIG. 18A is a timing chart of a follow-shot assist process bythe camera system 10. FIG. 18A illustrates a process timing in thecamera system 10 in the follow-shot assist mode and the live-viewimaging mode, where the attached interchangeable lens 200 is compatiblewith the follow-shot assist.

An image-capturing synchronizing signal 2001 is a synchronizing signaloutput from the timing generator 104. An image-capturing accumulation2002 represents an accumulation period in the image sensor 102, and theelectric charges are read in order from the top on the image in responseto the image-capturing synchronizing signal 2001. A synchronizing signalcommunication 2003 represents a timing of the synchronizing signalcommunication in the step S208 in FIG. 2. A set value communication 2004in the lens angular velocity detecting period represents a timing for aset value communication in the lens angular velocity detecting period inthe step S209 in FIG. 2.

A lens angular velocity communication 2005 represents a timing in thelens angular velocity communication in the step S1603 in FIG. 16. Anobject angular velocity communication 2006 represents a timing in theobject angular velocity communication in the step S1604 in FIG. 16. Anexposure timing communication 2007 represents a timing for thefollow-shot assist result communication in the step S1401 in FIG. 14. Alens angular velocity detecting period 2008 represents a lens angularvelocity detecting period set in the step S1502 in FIG. 15. When thelens angular velocity detecting period ends, the lens angular velocitycorresponding to this period is calculated and the lens angular velocityinformation tagged or correlated with the lens angular velocityinformation acquiring time is stored.

An angular velocity output 2009 represents an output from the angularvelocity detector 208. The lens controller 210 samples the angularvelocity output 2009 in the lens angular velocity detecting period 2008.An object movement correcting amount prediction 2010 in the follow-shotassist exposure represents reference time (or lens angular velocityinformation acquiring time t) in a process executed in the step S1702 inFIG. which calculates the drive amount of the image stabilizingcontroller 209 with a predictive expression so as to correct the objectmoving amount in exposure. A follow-shot assist correction process 2011represents a control period in the image stabilizing controller 209executed in the step S1703 in FIG. 17.

A description will now be given of a basic sequence for a follow-shotassist process in a live-view release exposure process. For example, inresponse to the image-capturing synchronizing signal 2012, asynchronizing signal communication 2013 is executed and the lenscontroller 210 calculates the inter-lens image-capturing synchronizingsignal time that coincides with the image-capturing synchronizing signal2012. Thereafter, a set value communication of the lens angular velocitydetecting period 2014 is executed. Thereby, the set value of the lensangular velocity detecting period 2015 is sent to the interchangeablelens 200 as time information corresponding to the motion vectordetecting time period and the start timing of the motion vectordetecting period 2016 in the camera body 100. The lens controller 210sets the lens angular velocity detecting period 2017. The lenscontroller 210 stores time information of the center of gravity time inthe lens angular velocity detecting period 2017 as the lens angularvelocity detecting time. A lens angular velocity communication 2018notifies the camera body 100 of the lens angular velocity detecting timeand the lens angular velocity information obtained after the lensangular velocity detecting period 2017 ends.

The camera body 100 when receiving the lens angular velocity informationgenerates the object angular velocity information based on the motionvector information detected in the motion vector detecting period 2016and the lens angular velocity information received from theinterchangeable lens 200. An object angular velocity communication 2019notifies the camera body 100 of the generated lens angular velocityinformation. The camera body 100 repeats the above processes andcontinues to send the accurate object angular velocity information tothe interchangeable lens 200, unless the photographer requests thelive-view release exposure process.

A description will now be given of a live-view release exposure processwhen the photographer presses the shutter switch 116 at a timing of alive-view release exposure process request 2020. Reference numeral 2021denotes the live-view release exposure process for still imagecapturing. The camera body 100 executes an exposure timing communication2023 at a timing a predetermined time period 2022 before the live-viewrelease exposure process 2021. Thereby, the camera body 100 sends astart timing for the live-view release exposure process for still imagecapturing to the interchangeable lens 200. While the communicationprocess notifies the exposure timing, the timing notifying method is notlimited to the communication.

When receiving the exposure timing communication 2007, the follow-shotassist controller 134 calculates a moving amount of the object in thelive-view release exposure process or a correction amount to drive theimage stabilizing controller 209 in exposure, in a period 2024. Thecalculation expression as used herein is the expression (1) describedwith reference to the step S1702 in FIG. 17. In the expression (1), thecurrent position T corresponds to the exposure start timing time, whichis the time made by adding the predetermined time period 2022 from thereception time of the exposure timing communication 2007 to the exposurestart. In addition, “ν” is lens angular velocity information obtained inthe lens angular velocity detecting period 2017, “a” is an objectangular velocity of which the object angular velocity communication 2019notifies the interchangeable lens 200, and “t” is lens angular velocityinformation acquiring time 2025. The image stabilizing controller 209 ismoved in a live-view release exposure process period 2027 so as tocorrect a moving amount of the object in a period illustrated by abroken line 2026. A description will be given of a method of calculatinga follow-shot correction amount in the described live-view releaseexposure process, with reference to FIG. 19.

In order to realize the follow-shot assist function, the object angularvelocity information is generated based on the angular velocitydetecting information of the interchangeable lens 200 and the motionvector detecting information of the camera body 100, and the objectangular velocity information is sent to the interchangeable lens 200.Thereby, in response to the live-view release exposure process request1020, a correcting amount by which the object moved up to the exposurecan be calculated.

FIG. 18A illustrates that the live-view release exposure process request1020 occurs when a series of information exchanges between the camerabody 100 and the interchangeable lens 200 are completed. Referring nowto FIG. 18B, a description will be given of a case where the live-viewrelease exposure process request occurs before the object angularvelocity information is transmitted from the camera body 100 to theinterchangeable lens 200.

In FIG. 18B, reference numerals 2001 to 2018 are the same as referencenumerals 2001 to 2018 in FIG. 18A, and the lens angular velocitycommunication 2018 notifies the camera body 100 of the lens angularvelocity information and the lens angular velocity detecting time.

The camera body 100 sends the object angular information to theinterchangeable lens 200 based on the motion vector information detectedin the motion vector detecting period 2016 and the angular velocityinformation detected in the lens angular velocity detecting period 2017.In FIG. 18B, the live-view release exposure process request 2020 occursbefore the object angular velocity information is communicated. In thiscase, the follow-shot assist process in the live-view release exposureprocess request 2020 is performed based on information in the lastimage-capturing synchronizing signal. In other words, theinterchangeable lens 200 notifies the camera body 100 of the lensangular velocity information and the lens angular velocity detectingtime through a lens angular velocity communication 2030 based on theangular velocity information detected in a lens angular velocitydetecting period 2029 illustrated by a broken line. The camera body 100generates motion vector information detected in a motion vectordetecting period 2028 illustrated by a broken line and angular velocityinformation detected in the lens angular velocity detecting period 2029illustrated by a broken line. The camera body 100 notifies theinterchangeable lens 200 of the generated object angular velocityinformation through an object angular velocity communication 2031. Atthis time, a lens angular velocity detecting time 2032 is stored in theobject angular velocity communication 2031. Thus, the follow-shot assistcontroller 134 does not have to store the lens angular velocityinformation acquiring time for each image-capturing synchronizing signalprocess. In other words, the follow-shot assist controller 134 cancalculates the drive amount for the image stabilizing controller 209 inthe live-view release exposure process with the expression (1) and onlyinformation received in the object angular velocity communication 2031.

In FIG. 18A, a series of information exchanges between the camera body100 and the interchangeable lens 200 are completed within thepredetermined image-capturing synchronizing signal period. However,another communication process, such as the AF and the AE, is performedbetween the camera body 100 and the interchangeable lens 200 in additionto the follow-shot assist communication. Hence, a communication band maynot be secured when the communication other than the follow-shot assistcommunication is performed, and for example, the lens angular velocitycommunication 2018 or the object angular velocity communication 2019cannot be completed within the predetermined image capturingsynchronizing period and may shift to the next image-capturingsynchronizing signal period. Referring now to FIG. 18C, a descriptionwill be given of this case.

FIG. 18C illustrates a process in the next image-capturing synchronizingsignal period as a result of that an object angular velocitycommunication 2033 cannot be completed in the predeterminedimage-capturing synchronizing signal period. In FIG. 18C, the live-viewrelease exposure process request 2020 occurs before the object angularvelocity communication 2033 is processed. In this case, in order totransfer to the live-view release exposure process, an object angularvelocity communication 2033 illustrated by a diagonal line is notexecuted. Hence, the follow-shot assist process is performed based onthe information in the last image-capturing synchronizing signal by thelive-view release exposure process request 2020. In other words, theinterchangeable lens 200 notifies the camera body 100 of the lensangular velocity information and the lens angular velocity detectingtime through the lens angular velocity communication 2030 based on theangular velocity information detected in the lens angular velocitydetecting period 2029 illustrated by a broken line. The camera body 100generates the object angular velocity information based on the motionvector information detected in the motion vector detecting period 2028illustrated by the broken line and the angular velocity informationdetected in the lens angular velocity detecting period 2029 illustratedby the broken line. The camera body notifies the interchangeable lens200 of the generated object angular velocity information through theobject angular velocity communication 2031. At this time, the lensangular velocity detecting time 2032 is stored in the object angularvelocity communication 2031. Therefore, the follow-shot assistcontroller 134 does not have to store the lens angular velocityinformation acquiring time for each image-capturing synchronizing signalprocess. In other words, the follow-shot assist controller 134 cancalculate the drive amount for the image stabilizing controller 209 inthe live-view release exposure process with the expression (1) and onlythe information received in the object angular velocity communication2031.

While this embodiment expresses the lens angular velocity communication2005 and the object angular velocity communication 2006 as separatecommunications, this embodiment may define a data format as a fullduplex communication and execute one communication process.

Referring now to FIG. 19, a description will be given of a drive amountcalculating method for the image stabilizing controller 209 in theexposure. FIG. is an explanatory view of the drive amount calculatingmethod for the image stabilizing controller 209 in exposure. In FIG. 19,an ordinate axis denotes an object angular velocity, and an abscissaaxis denotes time (elapsed time).

A point 2101 represents information in the lens angular velocitydetection as a start point for calculating the follow-shot assistcorrection amount. “t” is a lens angular velocity detecting time, and“ν” is object angular velocity information generated based on the motionvector information of the camera body 100 executed at the same timing asthe lens angular velocity detecting period and the lens angular velocitydetecting period. The lens angular velocity detecting time t is centerof gravity time in the lens angular velocity detecting period 1017 inFIG. 18A, and it is the center of gravity time in the lens angularvelocity detecting period 2029 in FIGS. 18B and 18C. The object angularvelocity information ν is information sent to the interchangeable lens200 in the object angular velocity communication 2019 in FIG. 18A, andthe information sent to the interchangeable lens 200 in the objectangular velocity communication 2031 in FIGS. 18B and 18C. The objectangular velocity information in the point 2101 contains the objectangular acceleration information “a,” and enables the object angularvelocity V in the live-view release exposure process in the point 2102to be linearly predicted with the predictive expression (expression(1)).

In this embodiment, the interchangeable lens sends the lens angularvelocity detecting time and the lens angular velocity detectinginformation to the camera body. The camera body generates the objectangular velocity information based on the lens angular velocityinformation and the motion vector information received from theinterchangeable lens, and sends the object angular velocity informationand the lens angular velocity detecting time to the interchangeablelens. This configuration can provide a lens interchangeable camerasystem having a follow-shot assist function which can properly predict amoving amount of an object and correct it with an image stabilizingcontroller in a live-view release exposure process operated by thephotographer at an arbitrary timing.

Fourth Embodiment

Next follows a description of a fourth embodiment according to thepresent invention. This embodiment more accurately corrects an objectmoving amount in the live-view release exposure process. The basisconfiguration of this embodiment is the same as that in the thirdembodiment.

The third embodiment linearly predicts the object moving amount inexposure by using one piece of object angular velocity information sentto the interchangeable lens 200 just before the live-view releaseexposure process, as illustrated in FIG. 19. In general, the camera body100 and the object gradually approach to each other in the imagecapturing scene that needs the follow shot, and thus the object movingamount to be corrected in exposure acceleratively increases. Hence, thelinear interpolation in the third embodiment may increase an error in aninterpolation amount. Accordingly, this embodiment stores a plurality ofpieces of object angular velocity information to be sent from the camerabody 100 to the interchangeable lens 200, and predicts the moving amountof the object in the live-view release exposure process with apolynomial.

Referring to FIG. 20, a description will be given of a follow-shotassist process in the camera system 10 (including the camera body 100and the interchangeable lens 200). FIG. 20 is a timing chart of thefollow-shot assist process in the camera system 10. FIG. 20 illustratesa process timing of the camera system 10 in the follow-shot assist modein the live-view imaging mode where the attached interchangeable lens200 is compatible with the follow-shot assist. In FIG. 20, referencenumerals 2001 to 2027 are the same as reference numerals 2001 to 2027 inFIG. 18A described in the third embodiment.

Unlike the third embodiment, this embodiment uses the object angularvelocity information in two periods, i.e., the motion vector detectingperiod 2028 (with the same timing as that of the lens angular velocitydetecting period 2029) and the motion vector detecting period 2016 (withthe same timing as that of the lens angular velocity detecting period2017). The object angular velocity information in the motion vectordetecting period 2028 is sent to the interchangeable lens 200 by theobject angular velocity communication 2031. The object angular velocityinformation in the motion vector detecting period 2016 is sent to theinterchangeable lens 200 by the object angular velocity communication2019.

Referring now to FIG. 21, a description will be given of the calculationmethod of the drive amount of the image stabilizing controller 209 inexposure. FIG. 21 is an explanatory view of a calculation method of adrive amount of the image stabilizing controller 209 in exposure. InFIG. 21, an ordinate axis denotes an object angular velocity, and anabscissa axis denotes time (elapsed time).

In FIG. 21, a point 2201 represents information sent to theinterchangeable lens 200 by the object angular velocity communication2031, and contains information of an object angular velocity ν1 and anobject angular acceleration a1 at time t1. A point 2202 representsinformation sent to the interchangeable lens 200 by the object angularvelocity communication 1019, and contains information of an objectangular velocity ν2 and an object angular acceleration a2 at time t2.

A secondary predictive expression can be calculated based on theinformation at these two points (points 2201 and 2202), and thisembodiment makes a calculation with the following expression (3).

$\begin{matrix}{{Y = {{Ax}^{2} + {Bx} + C}}{A = \frac{\left( {{a\; 1} - {a\; 2}} \right)}{2\left( {{t\; 1} - {t\; 2}} \right)}}{B = \frac{\left\{ {{2\left( {{v\; 1} - {v\; 2}} \right)} - {\left( {{a\; 1} - {a\; 2}} \right)\left( {{t\; 1} - {t\; 2}} \right)}} \right\}}{2\left( {{t\; 1} - {t\; 2}} \right)}}{C = {{v\; 1} - \frac{\left( {{a\; 1} - {a\; 2}} \right)t\; 1^{2}}{2\left( {{t\; 1} - {t\; 2}} \right)} - \frac{t\; 1\left\{ {{2\left( {{v\; 1} - {v\; 2}} \right)} - {\left( {{a\; 1} - {a\; 2}} \right)\left( {{t\; 1} + {t\; 2}} \right)}} \right\}}{2\left( {{t\; 1} - {t\; 2}} \right)}}}} & (3)\end{matrix}$

Object angular velocity information V in exposure or at a point 2203 iscalculated with the expression (3). This embodiment calculates an objectmoving amount in the live-view release exposure process based on theobject velocity information at two points before the live-view releaseexposure process, but may use a polynomial for the prediction with threeor more points.

In this embodiment, the interchangeable lens sends the lens angularvelocity detecting information and the lens angular velocity detectingtime to the camera body. The camera body generates the object angularvelocity information based on the lens angular velocity information andthe motion vector information received from the interchangeable lens,and sends the generated object angular velocity information and lensangular velocity detecting time to the interchangeable lens. Due to thisconfiguration, the interchangeable lens can precisely predict the movingamount of the object in exposure using a plurality of pieces of objectangular velocity information and angular velocity detecting time. Hence,this embodiment can provide a lens interchangeable camera systemequipped with the follow-shot assist function, which can more accuratelypredict a moving amount of the object in exposure and correct the movingamount with the image stabilizing controller.

In each embodiment, the control apparatus in the camera body 100includes a calculator (follow-shot assist controller 134) and acommunicator (lens communication controller 133) configured to receivethe angular velocity detected in the angular velocity detecting periodand the angular velocity detecting time information. The calculatorcalculates the angular velocity information of the object based on themotion vector and the angular velocity. The communicator sends theobject angular velocity information the angular velocity detecting timeinformation correlated with each other and the exposure start timing.

In each embodiment, the control apparatus in the interchangeable lens200 includes a communicator (I/F 220) configured to receive the angularvelocity detecting period set based on the motion vector detectingperiod, and the calculator (lens controller 210) configured to calculatethe object angular velocity information in exposure. The communicator(communication unit) sends the angular velocity detected in the angularvelocity detecting period and the angular velocity detecting timeinformation, receives the calculated object angular velocity informationcorrelated with the angular velocity detecting time information based onthe motion vector and the angular velocity, and receives the exposurestart timing. The calculator calculates the object angular velocityinformation in exposure based on the received object angular velocityinformation, the angular velocity detecting time information, and theexposure start timing. The calculator may control an image stabilizationbased on the object angular velocity information in exposure. Thecalculator may calculate the object angular velocity information inexposure based on the object angular velocity information received justbefore the exposure start timing. The communicator may receive aplurality of pieces of object angular velocity information obtained atdifferent timings before receiving the exposure start timing. Thecommunicator calculates the object angular velocity information inexposure by using a plurality of pieces of the object angular velocityinformation. The communicator may transmit the angular velocity detectedin the angular velocity detecting period and receive the object angularvelocity information in the same communication process by a full duplexcommunication.

Each embodiment can provide a control apparatus, an image capturingapparatus, a lens apparatus, a control method, and a storage medium,which can feed back a follow-shot assist result to a photographer when afollow-shot correction amount exceeds a movable range of an imagestabilizing control lens, or improve a follow-shot assist performance.

Other Embodiments

Embodiment(s) of the present invention can also be realized by acomputer of a system or apparatus that reads out and executes computerexecutable instructions (e.g., one or more programs) recorded on astorage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Applications Nos.2016-145112 and 2016-145254, each filed on Jul. 25, 2016, which arehereby incorporated by reference herein in their entirety.

What is claimed is:
 1. A control apparatus comprising: a motion vectordetector configured to detect a motion vector; a calculator configuredto calculate angular velocity information of an object based on themotion vector and an angular velocity detected by an angular velocitydetector; an acquirer configured to acquire a result of an imagestabilizing control in capturing a still image based on the angularvelocity information of the object; and a controller configured tocontrol a display unit so as to display the still image and informationof the result of the image stabilizing control superimposed on the stillimage.
 2. The control apparatus according to claim 1, wherein theacquirer acquires the result of the image stabilizing control from alens apparatus through a communication after the still image iscaptured.
 3. The control apparatus according to claim 1, wherein thedisplay unit displays the information of the result of the imagestabilizing control superimposed on information of an object position inthe still image.
 4. The control apparatus according to claim 1, whereinthe information of the result of the image stabilizing control containsinformation on whether an image stabilizing lens in a lens apparatusexceeds a movable range in capturing the still image.
 5. The controlapparatus according to claim 1, wherein the information of the result ofthe image stabilizing control contains information on the angularvelocity in capturing the still image and information on a predictedangular velocity of the object calculated before the still image iscaptured.
 6. A control apparatus comprising: an angular velocitydetector configured to detect an angular velocity; an image stabilizingcontroller configured to perform an image stabilizing control incapturing a still image by using angular velocity information of anobject calculated based on the angular velocity and a motion vectordetected by a motion vector detector; and a communicator configured totransmit a result of the image stabilizing control after the still imageis captured.
 7. The control apparatus according to claim 6, wherein theimage stabilizing controller determines whether an image stabilizinglens exceeds a movable range in capturing the still image, and whereinthe result of the image stabilizing control contains information onwhether the image stabilizing lens exceeds the movable range incapturing the still image.
 8. The control apparatus according to claim6, further comprising a predictor configured to calculate a predictedangular velocity of the object before the still image is captured,wherein the angular velocity detector detects the angular velocity inthe still image capturing, and the result of the image stabilizingcontrol contains the predicted angular velocity and the angular velocityof the object.
 9. An image capturing apparatus to which a lens apparatusis detachably attached, the image capturing apparatus comprising: animage sensor configured to photoelectrically convert an optical imageformed via the lens apparatus; a motion vector detector configured todetect a motion vector based on an image signal output from the imagesensor; a calculator configured to calculate angular velocityinformation of an object based on the motion vector and an angularvelocity detected by an angular velocity detector; an acquirerconfigured to acquire a result of an image stabilizing control incapturing a still image based on the angular velocity information of theobject; and a controller configured to control a display unit so as todisplay the still image and information of the result of the imagestabilizing control superimposed on the still image.
 10. A lensapparatus attached to and detached from an image capturing apparatus,the lens apparatus comprising: an image capturing optical system thatincludes an image stabilizing control lens; an angular velocity detectorconfigured to detect an angular velocity of the lens apparatus; an imagestabilizing controller configured to perform an image stabilizingcontrol in capturing a still image by using angular velocity informationof an object calculated based on the angular velocity and a motionvector detected by a motion vector detector; and a communicatorconfigured to transmit a result of the image stabilizing control afterthe still image is captured.
 11. An image capturing system comprising animage capturing apparatus and a lens apparatus, the image capturingsystem further comprising: an image capturing optical system thatincludes an image stabilizing control lens; an image sensor configuredto photoelectrically convert an optical image formed via the lensapparatus; a motion vector detector configured to detect a motion vectorbased on an image signal output from the image sensor; a calculatorconfigured to calculate angular velocity information of an object basedon the motion vector and an angular velocity detected by an angularvelocity detector; an acquirer configured to acquire a result of animage stabilizing control in capturing a still image based on theangular velocity information of the object; and a controller configuredto control a display unit so as to display the still image andinformation of the result of the image stabilizing control superimposedon the still image.
 12. A control method comprising the steps of:detecting a motion vector; calculating angular velocity information ofan object based on the motion vector and an angular velocity of anapparatus; acquiring a result of an image stabilizing control incapturing a still image based on the angular velocity information of theobject; and controlling a display unit so as to display the still imageand information of the result of the image stabilizing controlsuperimposed on the still image.
 13. A control method comprising thesteps of: detecting an angular velocity of an apparatus; performing animage stabilizing control in capturing a still image by using angularvelocity information of an object calculated based on the angularvelocity and a motion vector; and transmitting a result of the imagestabilizing control after the still image is captured.
 14. Anon-transitory computer-readable storage medium for storing a programthat enables a computer to execute a control method, wherein the controlmethod includes the steps of: detecting a motion vector; calculatingangular velocity information of an object based on the motion vector andan angular velocity of an apparatus; acquiring a result of an imagestabilizing control in capturing a still image based on the angularvelocity information of the object; and controlling a display unit so asto display the still image and information of the result of the imagestabilizing control superimposed on the still image.
 15. Anon-transitory computer-readable storage medium for storing a programthat enables a computer to execute a control method, wherein the controlmethod includes the steps of: detecting an angular velocity of anapparatus; performing an image stabilizing control in capturing a stillimage by using angular velocity information of an object calculatedbased on the angular velocity and a motion vector; and transmitting aresult of the image stabilizing control after the still image iscaptured.
 16. A control apparatus comprising: a motion vector detectorconfigured to detect a motion vector; a calculator configured to set adetecting period of an angular velocity by an angular velocity detectorbased on a detecting period of the motion vector; and a communicatorconfigured to receive the angular velocity detected in the detectingperiod of the angular velocity and detecting time information of theangular velocity, wherein the calculator calculates angular velocityinformation of the object based on the motion vector and the angularvelocity; and wherein the communicator transmits the angular velocityinformation of the object and the detecting time information of theangular velocity correlated with each other, and receives an exposurestart timing.
 17. A control apparatus comprising: a communicatorconfigured to receive a detecting period of an angular velocity setbased on a detecting period of a motion vector; an angular velocitydetector configured to detect the angular velocity in the detectingperiod of the angular velocity; and a calculator configured to calculateangular velocity information of an object in exposure, wherein thecommunicator transmits the angular velocity detected in the detectingperiod of the angular velocity and detecting time information of theangular velocity, receives angular velocity information of the objectcalculated based on the motion vector and the angular velocity andcorrelated with the detecting time information of the angular velocity,and receives an exposure start timing, and wherein the communicatorcalculates angular velocity information of the object in exposure basedon received angular velocity information of the object, the detectingtime information of the angular velocity, and the exposure start timing.18. The control apparatus according to claim 17, wherein the calculatorprovides an image stabilizing control based on the angular velocityinformation of the object in exposure.
 19. The control apparatusaccording to claim 17, wherein the calculator calculates the angularvelocity information of the object in exposure based on the angularvelocity information of the object received just before the exposurestart timing.
 20. The control apparatus according to claim 17, whereinthe communicator receives a plurality of pieces of angular velocityinformation of the object obtained at different timings before receivingthe exposure start timing, and wherein the calculator calculates theangular velocity information of the object in exposure using theplurality of pieces of angular velocity information of the object. 21.The control apparatus according to claim 17, wherein the communicatortransmits the angular velocity detected in the detecting period of theangular velocity and receives the angular velocity information of theobject in the same communication process through a full duplexcommunication.
 22. An image capturing apparatus to which a lens isdetachably attached, the image capturing apparatus comprising: an imagesensor configured to photoelectrically convert an optical image formedvia the lens apparatus; a motion vector detector configured to detect amotion vector based on an image signal output from the image sensor; acalculator configured to set a detecting period of an angular velocityby an angular velocity detector based on a detecting period of themotion vector; and a communicator configured to receive the angularvelocity detected in the detecting period of the angular velocity anddetecting time information of the angular velocity, wherein thecalculator calculates angular velocity information of the object basedon the motion vector and the angular velocity; and wherein thecommunicator transmits the angular velocity information of the objectand the detecting time information of the angular velocity correlatedwith each other, and receives an exposure start timing.
 23. A lensapparatus attached to and detached from an image capturing apparatus,the lens apparatus comprising: an image capturing optical system; acommunicator configured to receive a detecting period of an angularvelocity set based on a detecting period of a motion vector; an angularvelocity detector configured to detect the angular velocity in thedetecting period of the angular velocity; and a calculator configured tocalculate angular velocity information of an object in exposure, whereinthe communicator transmits the angular velocity detected in thedetecting period of the angular velocity and detecting time informationof the angular velocity to the image capturing apparatus, receives theangular velocity information of the object calculated based on themotion vector and the angular velocity from the image capturingapparatus, and receives an exposure start timing from the imagecapturing apparatus, and wherein the communicator calculates the angularvelocity information of the object in exposure based on received angularvelocity information of the object, the detecting time information ofthe angular velocity, and the exposure start timing.
 24. A controlmethod comprising the steps of: detecting a motion vector; setting adetecting period of an angular velocity by an angular velocity detectorbased on a detecting period of the motion vector; receiving the angularvelocity detected in the detecting period of the angular velocity anddetecting time information of the angular velocity; calculating angularvelocity information of the object based on the motion vector and theangular velocity; transmitting the angular velocity information of theobject and the detecting time information of the angular velocitycorrelated with each other; and receiving an exposure start timing. 25.A control method comprising the steps of: receiving a detecting periodof an angular velocity set based on a detecting period of a motionvector; detecting the angular velocity in the detecting period of theangular velocity; transmitting the angular velocity detected in thedetecting period of the angular velocity and detecting time informationof the angular velocity; receiving angular velocity information of anobject calculated based on the motion vector and the angular velocityand correlated with the detecting time information of the angularvelocity; receiving an exposure start timing; and calculating angularvelocity information of the object in exposure based on received angularvelocity information of the object, the detecting time information ofthe angular velocity, and the exposure start timing.
 26. Anon-transitory computer-readable storage medium for storing a programthat enables a computer to execute a control method, wherein the controlmethod includes the steps of: detecting a motion vector; setting adetecting period of an angular velocity by an angular velocity detectorbased on a detecting period of the motion vector; receiving the angularvelocity detected in the detecting period of the angular velocity anddetecting time information of the angular velocity; calculating angularvelocity information of the object based on the motion vector and theangular velocity; transmitting the angular velocity information of theobject and the detecting time information of the angular velocitycorrelated with each other; and receiving an exposure start timing. 27.A non-transitory computer-readable storage medium for storing a programthat enables a computer to execute a control method, wherein the controlmethod includes the steps of: receiving a detecting period of an angularvelocity set based on a detecting period of a motion vector; detectingthe angular velocity in the detecting period of the angular velocity;transmitting the angular velocity detected in the detecting period ofthe angular velocity and detecting time information of the angularvelocity; receiving angular velocity information of an object calculatedbased on the motion vector and the angular velocity and correlated withthe detecting time information of the angular velocity; receiving anexposure start timing; and calculating angular velocity information ofthe object in exposure based on received angular velocity information ofthe object, the detecting time information of the angular velocity, andthe exposure start timing.